V1054 Ophiuchi

V1054 Ophiuchi

An ultraviolet band light curve for a flare on V1054 Ophiuchi, plotted from data published by Dal and Evren (2010)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ophiuchus[2]
AB
Right ascension 16h 55m 28.75757s[3]
Declination −08° 20′ 10.7878″[3]
Apparent magnitude (V) 9.74/10.34/10.84[4]
Gliese 643
Right ascension 16h 55m 25.22225s[5]
Declination −08° 19′ 21.2970″[5]
Apparent magnitude (V) 11.74[4]
C (VB 8)
Right ascension 16h 55m 35.25574s[6]
Declination −08° 23′ 40.7531″[6]
Apparent magnitude (V) 16.80[4]
Characteristics
AB
Spectral type M3 V[7] / M4 Ve[note 1]
Gliese 643
Spectral type M3.5 V[7]
C (VB 8)
Spectral type M7.0 V[4]
Astrometry
AB
Radial velocity (Rv)14.89±0.05[8] km/s
Proper motion (μ) RA: −817.84±6.68 mas/yr[3]
Dec.: −873.53±3.53 mas/yr[3]
Parallax (π)161.41±5.64 mas[3]
Distance20.2 ± 0.7 ly
(6.2 ± 0.2 pc)
Absolute magnitude (MV)10.23[2]
Gliese 643
Radial velocity (Rv)15.20±0.15[5] km/s
Proper motion (μ) RA: −817.580(52) mas/yr[5]
Dec.: −898.595(40) mas/yr[5]
Parallax (π)153.8754±0.0474 mas[5]
Distance21.196 ± 0.007 ly
(6.499 ± 0.002 pc)
Absolute magnitude (MV)12.60[2]
VB 8
Proper motion (μ) RA: −813.038(63) mas/yr[6]
Dec.: −870.609(44) mas/yr[6]
Parallax (π)153.9659 ± 0.0570 mas[6]
Distance21.184 ± 0.008 ly
(6.495 ± 0.002 pc)
Absolute magnitude (MV)17.75[4]
Orbit[7]
PrimaryV1054 Oph A
CompanionV1054 Oph B
Period (P)1.717267±0.000039[4] yr
Semi-major axis (a)0.2273±0.0004"
(1.46683 AU[note 2])
Eccentricity (e)0.042±0.001
Inclination (i)160.3±0.1°
Longitude of the node (Ω)−10.2±0.2°
Periastron epoch (T)MJD 53943±3
Argument of periastron (ω)
(secondary)		306.0±1.5°
Orbit[7]
PrimaryV1054 Oph Ba
CompanionV1054 Oph Bb
Period (P)2.965509±0.000006 d
Semi-major axis (a)0.00687[note 3]"
(0.04432 AU[note 4])
Eccentricity (e)0.0209±0.0008
Inclination (i)164.18±0.08°
Periastron epoch (T)MJD 50919.48±0.03
Argument of periastron (ω)
(secondary)		150.0±3.0°
Details
AB
Mass0.4155±0.0057 / 0.3466±0.0047 / 0.3143±0.0040[7] M☉
Gliese 643
Mass0.19[4] M☉
C (VB 8)
Mass0.0914+0.0026
−0.0025[9] M☉
Radius0.1214+0.0060
−0.0057[9] R☉
Luminosity0.000645+0.000004
−0.000005[9] L☉
Temperature2,640+65
−64[9] K
Other designations
CCDM J16555-0820
AB: V1054 Oph, BD−08°4352, GJ 644, HD 152751, HIP 82817, SAO 141439, LHS 428, Wolf 630[10]
GJ 643: GJ 643, HIP 82809, LHS 427, Wolf 629[11]
C: GJ 644 C, LHS 429, VB 8[12]
Database references
SIMBADABab
GJ 643
C (vB 8)

V1054 Ophiuchi, together with the star Gliese 643, is a nearby quintuple star system, located in the constellation Ophiuchus at a distance of 21.2 light-years. It consists of five stars, all of which are red dwarfs. The alternative designation of Wolf 630 forms the namesake of a moving group of stars that share a similar motion through space.[13]

Overview

A
P = 1.72 yr
Ba
P = 2.97 d
Bb
72″ separation
GJ 643
220″ separation
C (VB 8)

Hierarchy of orbits in the system[4]

V1054 Ophiuchi/Gliese 643 is the nearest quintuple star system;[4] the next nearest star systems with at least five stars are Xi Ursae Majoris (quintuple, including a brown dwarf)[14] at 28.5 light-years, Castor[4] (sextuple) at 49.2 light-years, and GJ 2069 (quintuple)[7] at 54.3 light-years. V1054 Ophiuchi and Xi Ursae Majoris are the only two quintuple star systems within 10 parsecs.[14]

The system consists of three widely separated parts:

  • close triple subsystem V1054 Ophiuchi A-Bab (including very close binary subsystem V1054 Ophiuchi Bab)
  • Gliese 643
  • V1054 Ophiuchi C (vB 8)

The brightest and most massive of these five stars is V1054 Ophiuchi A. The close binary subsystem V1054 Ophiuchi B is more massive than V1054 Ophiuchi A, however, its total visual magnitude is 0.1 mag fainter than V1054 Ophiuchi A's visual magnitude.[4]

The total apparent magnitude of the V1054 Ophiuchi A-Bab triple subsystem is 9.02.[4][15]

Despite V1054 Ophiuchi/Gliese 643 consisting of low-mass stars, the system's total mass, due to the large number of components, exceeds the Solar mass,[4] (it is about 1.35 M☉).

Distance

Currently, the most accurate distance estimate of V1054 Ophiuchi/Gliese 643 is a trigonometric parallax of Gliese 643 from Gaia DR3:[5] 153.8754±0.0474 mas, corresponding to a distance of 6.499±0.002 pc, or 21.196±0.007 ly.

Past V1054 Ophiuchi/Gliese 643 distance estimates

V1054 Ophiuchi A-Bab:

SourcePaperParallax, masDistance, pcDistance, lyRef.
WoolleyWoolley et al. 1970156 ± 46.41 ± 0.1720.9 ± 0.6[16]
GJ, 3rd versionGliese & Jahreiß 1991153.9 ± 2.66.50 ± 0.1121.19 ± 0.36[17]
YPC, 4th editionvan Altena et al. 1995154.8 ± 0.66.460 ± 0.02521.07 ± 0.08[18]
HipparcosPerryman 1997174.23 ± 3.905.74 ± 0.1318.7 ± 0.4[15]
SoederhjelmSoederhjelm 1999155.63 ± 1.816.43 ± 0.0820.96 ± 0.25[19]
Hipparcos2van Leeuwen 2007161.41 ± 5.646.20 ± 0.2220.21 ± 0.73[3]

Gliese 643:

SourcePaperParallax, masDistance, pcDistance, lyRef.
WoolleyWoolley et al. 1970169 ± 55.92 ± 0.1819.3 ± 0.6[16]
GJ, 3rd versionGliese & Jahreiß 1991171.9 ± 7.35.82 ± 0.2619.0 ± 0.8[17]
YPC, 4th editionvan Altena et al. 1995169.8 ± 6.65.89 ± 0.2419.2 ± 0.8[18]
HipparcosPerryman 1997153.96 ± 4.046.50 ± 0.1821.2 ± 0.6[15]
Hipparcos2van Leeuwen 2007148.92 ± 4.006.72 ± 0.1921.9 ± 0.6[3]

V1054 Ophiuchi C (vB 8):

SourcePaperParallax, masDistance, pcDistance, lyRef.
CTIOPI 1.5 mTSN 14 (Costa et al. 2005)155.43 ± 1.336.43 ± 0.0620.98 ± 0.18[20]

Weighted mean distance

A weighted mean parallax[21] was calculated by RECONS in 2012, considering YPC (V1054 Ophiuchi A-Bab and Gliese 643), Hipparcos (Soederhjelm — V1054 Ophiuchi A-Bab and van Leeuwen — Gliese 643) and CTIOPI (V1054 Ophiuchi C) data. The value is 154.96±0.52 mas,[22] corresponding to a distance of 6.453±0.022 pc, or 21.05±0.07 ly. This predates Gaia astrometry of the system.

System

V1054 Ophiuchi A-Bab (inner triple subsystem)

V1054 Ophiuchi A-Bab is a close spectroscopic triple subsystem, consisting of the brighter component V1054 Ophiuchi A and the more massive binary subsystem V1054 Ophiuchi Bab, orbiting each other with a period of 627 days,[7][4] or 1.72 years.[4] V1054 Ophiuchi Bab components are orbiting each other with a period of 2.9655 days.[7][4] Both outer and inner orbits are nearly circular and, probably, coplanar[7][4] (in keeping with a general tendency of close triple systems).[7]

V1054 Ophiuchi A-Bab pair is also visually resolved (for nearly 50 years it was the shortest-period resolved by visual means binary, since its binarity was discovered by G. P. Kuiper in 1934),[4] whereas V1054 Ophiuchi Ba-Bb pair is still unresolved).[7][4][note 5]

Gliese 643

The projected separation of Gliese 643 from V1054 Ophiuchi A-Bab is 72 arcsec,[7] corresponding at 21.05 light-years to 465 a.u.

V1054 Ophiuchi C (vB 8)

vB 8 is the smallest, faintest, and most separated component of the V1054 Ophiuchi system. The projected separation of the red dwarf from the primary triple system is about 220 arcsec,[7][4] corresponding at 21.05 light-years to 1420 a.u. Since it is only three times larger than the projected separation between Gliese 643 and V1054 Ophiuchi A-Bab, and such a small ratio should render the triple system dynamically unstable, it was suggested[4] that the real separation of V1054 Ophiuchi C from V1054 Ophiuchi A-Bab is much larger, at least by a factor of two,[4] i. e. at least 2840 a.u.

In 1984, the apparent detection of an infrared source near vB 8 suggested it had a low mass companion. The low mass of this candidate led to speculation that it may be a brown dwarf; the first such to be detected. This discovery was later found to be spurious, but it produced much interest in this class of astronomical object.[23]

Notes

  1. ↑ Referred to entire V1054 Ophiuchi Bab subsystem.
  2. ↑ Assuming weighted mean parallax 154.96 mas.
  3. ↑ From masses, period and parallax.
  4. ↑ From masses and period. According to Mazeh et al. 2001, of order of 0.05 a. u.
  5. ↑ At least it was not resolved by 2001.

References

  1. ↑ Dal, H. A.; Evren, S. (August 2010). "A New Method for Classifying Flares of UV Ceti Type Stars: Differences Between Slow and Fast Flares". The Astronomical Journal. 140 (2): 483–489. arXiv:1206.5791. Bibcode:2010AJ....140..483D. doi:10.1088/0004-6256/140/2/483. S2CID 119308060. Retrieved 4 February 2022.
  2. 1 2 3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
  3. 1 2 3 4 5 6 7 Vizier, Hipparcos, the New Reduction (van Leeuwen 2007)
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Mazeh, Tsevi; Latham, David W.; Goldberg, Elad; Torres, Guillermo; Stefanik, Robert P.; Henry, Todd J.; Zucker, Shay; Gnat, Orly; Ofek, Eran O. (2001). "Studies of multiple stellar systems - IV. The triple-lined spectroscopic system V1054 Ophiuchi". Monthly Notices of the Royal Astronomical Society. 325 (1): 343–357. arXiv:astro-ph/0102451. Bibcode:2001MNRAS.325..343M. doi:10.1046/j.1365-8711.2001.04419.x. S2CID 16472347.
  5. 1 2 3 4 5 6 7 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  6. 1 2 3 4 5 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 Ségransan, Damien; Delfosse, Xavier; Forveille, Thierry; Beuzit, Jean-Luc; Udry, Stéphane; Perrier, Christian; Mayor, Michel (2000). "Accurate masses of very low mass stars. III. 16 new or improved masses". Astronomy and Astrophysics. 364: 665–673. arXiv:astro-ph/0010585. Bibcode:2000A&A...364..665S.
  8. ↑ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424: 727. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213.
  9. 1 2 3 4 Pineda, J. Sebastian; Youngblood, Allison; France, Kevin (September 2021). "The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars". The Astrophysical Journal. 918 (1): 23. arXiv:2106.07656. Bibcode:2021ApJ...918...40P. doi:10.3847/1538-4357/ac0aea. S2CID 235435757. 40.
  10. ↑ "HD 152751". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-25.
  11. ↑ "GJ 643". SIMBAD. Centre de données astronomiques de Strasbourg.
  12. ↑ "VB 8". SIMBAD. Centre de données astronomiques de Strasbourg.
  13. ↑ Bubar, Eric J.; King, Jeremy R. (August 2010). "Spectroscopic Abundances and Membership in the Wolf 630 Moving Group". The Astronomical Journal. 140 (2): 293–318. arXiv:1005.1205. Bibcode:2010AJ....140..293B. doi:10.1088/0004-6256/140/2/293. S2CID 118455341.
  14. 1 2 Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (30 April 2021). "The 10 parsec sample in the Gaia era". Astronomy & Astrophysics. 650: A201. arXiv:2104.14972. Bibcode:2021A&A...650A.201R. doi:10.1051/0004-6361/202140985. S2CID 233476431. Data available at https://gruze.org/10pc/ Archived 12 March 2023 at the Wayback Machine
  15. 1 2 3 Vizier, The Hipparcos and Tycho Catalogues (ESA 1997)
  16. 1 2 Vizier, Stars within 25 pc of the Sun (Woolley+ 1970)
  17. 1 2 Vizier, Nearby Stars, Preliminary 3rd Version (Gliese+ 1991)
  18. 1 2 VizieR, Yale Trigonometric Parallaxes, Fourth Edition (van Altena+ 1995)
  19. ↑ Vizier, Visual binary orbits and masses (Soederhjelm 1999)
  20. ↑ Costa, Edgardo; Méndez, René A.; Jao, W.-C.; Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Ianna, Philip A.; Bartlett, Jennifer (2005). "The Solar Neighborhood. XIV. Parallaxes from the Cerro Tololo Inter-American Observatory Parallax Investigation-First Results from the 1.5 m Telescope Program". The Astronomical Journal. 130 (1): 337–349. Bibcode:2005AJ....130..337C. CiteSeerX 10.1.1.573.7563. doi:10.1086/430473. S2CID 12213270.
  21. ↑ DENSE Project. 25 pc White Dwarf Sample (see formulae below)
  22. ↑ THE ONE HUNDRED NEAREST STAR SYSTEMS brought to you by RECONS (Research Consortium On Nearby Stars)
  23. ↑ Reid, Neill I.; Hawley, Suzanne L. (27 November 2013). New Light on Dark Stars: Red Dwarfs, Low-Mass Stars, Brown Dwarfs. Astronomy and Planetary Sciences. Springer Science & Business Media, 2013. p. 344. ISBN 978-1447136637.
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